My daughter and I were just wondering whether some lip balm is OK which said Use By 2004 on it, and I found this site which gives the expiration dates for a lot of things. I was surprised that lip balm can last up to 5 years apparently. (Which makes my lip balm a bit old to keep!)
One thing it said which I disagree with is that soap only lasts up to 3 years. I am sure that is wrong? as I have kept bars of soap for over ten years and they are still perfect.
It's a still useful guide though; here is the site, it may be useful for somebody for working out what to chuck out.